The optical response of a complex nanodimer composed of a metal nanoparticle and a quantum dot: The effect of nanoparticle geometry

Abstract

The optical response of a hybrid structure consisting of a metal nanoparticle in the vicinity of a quantum dot under an external field is studied. The effect of the nanoparticle shape as it evolves from a sphere to a rod is investigated for various structural parameters. Significant changes are observed in the phase diagram of the optical response at the borders between Fano, exciton-induced transparency, suppression, and bistable regions. In the appropriate limits, the configuration exhibits a response where notable variations are particularly observed in suppression and bistable regions. In the presence of the nanorod, the suppression region is found as the beginning of bistability. Our calculations show that the nanorod can generate significant nonlinearities at the site of quantum dot in the bistable region, making the hybrid structure suitable for devices involving optical switching or information transfer. By considering the effect of other structural parameters, for example the configuration state, background dielectric constant, and interparticle distance, one can obtain additional control of the optical response of the system, engineering it to achieve particular objectives.